Chapter four opens with a discussion between Land and Aronnax of where the vessel is headed. Aronnax does not know, nor does he seem to care. He is enjoying his adventure aboard the Nautilus, and notes that like Nemo, he has become a fanatic. Land grumbles that they have been imprisoned for three months.
Aronnax describes the scientific aspects of the Red Sea to the reader, and wonders why Nemo would head there, which is where it seems they are going--although he is not critical of the captain's decision at all. Aronnax continues to enjoy the sights of the sea through the viewing windows in the salon.
Captain Nemo joins Aronnax in the salon and the men engage in a discussion
of the dangers of the Red Sea, to which the Nautilus is immune.
Aronnax is surprised to hear they will be venturing into the Mediterranean
the next day, because he knows how far the Cape of Good Hope is from their
present location. The captain tells Aronnax that there is tunnel at the
bottom of the sea that will allow them to pass out of the Red Sea without
having to go to Africa at all. When Aronnax inquires how Nemo found this
passage, Nemo tells him there can be no secrets between people who are
never to part. Aronnax decides not to react to Nemo's statement. Nemo
explains how he reason there must be a tunnel by observing fish species.
Ned Land is suspicious of the tunnel, because he has never heard of it. On the way to the tunnel the men observe a dugong, a curious and almost extinct creature. Land first instinct was to kill the creature, because he had never killed one like it before. Land is interested in eating the creature. Conseil suggests that because it is so rare it should be left alone, for the purposes of science. Land believes it is more valuable for the purpose of eating. Land, Conseil and Aronnax set out in the small boat to hunt the creature.
Upon first try, Land barely injures the animal and it swims away--the boat chases. The dugong returns to the boat, attacking it. The boat nearly capsizes, but Land manages to kill the creature.
The next day the Nautilus makes it through the Arabian Tunnel.
In this section the men hunt for pearls. It is important to note Nemo's cultivation of the giant pearl. He wants to leave it undisturbed so that it will become greater. This is juxtaposition with the Nautilus. The longer the vessel remains undiscovered the more powerful it becomes. Like the Nautilus, pearls have different kinds of power. Like Land, many men are interested in the financial gain they promise; like the divers, many risk and lose their lives in pursuit of the pearls. However, the peals also have an aesthetic value. For this value, Aronnax prizes them. Similarly, the Nautilus is used for good and evil. Through their experiences on the ship, Captain Nemo and Aronnax will be able to significantly contribute to the scientific community and benefit mankind. However, the ship is also used to destroy humanity.
When Nemo saves the life of the diver, the reader experiences yet another side of this complex character. He seems intent on killing innocent people, but he saves this one life. He remarks that this man is oppressed. It seems there is a political agenda to Nemo's madness. He must be killing certain people.
Ned Land continues to require tangible proof in order to believe something
exists. He cannot be convinced of the Arabian Tunnel until he experiences
it. He, like Aronnax, has a certain arrogance about him. He does not think
something can exist unless he knows about it. When Land encounters the
dugong he must kill it because he has never killed one before. Aronnax
wonders if they should leave it for the benefit of science. Land continues
be a man of action, while Aronnax is much more cerebral.